Means and method of defoaming



Patented May 8, 1934 UNITED STATES PATENT OFFICE IHEANS AND METHOD OF DEFOAMING No Drawing.

Application October 18. 1928,

Serial No. 313,375

15 Claims.

My invention relates to processes for preventing the foaming of those compounds and mixtures which have a tendency to foam, especially when their solution is attempted with the assistance of heat.

There are many compounds which have the undesirable property of foaming when heated alone or when heated in the presence of substances intended to maintain them in solution or emulsion.

I have found that when water insoluble metallic soaps are suitably dispersed in water, such dispersions will defoam these foamable compounds or mixtures.

I have further found that a dispersion or emulsion of such water insoluble metallic soap can be best prepared by first dissolving the metallic soap in an organic solvent, among which are paraffin wax, fatty acids, pine oil and kerosene and then dispersing the solution in water with a suitable dispersing agent, among which are sulphonated oil and sulphonated tallow.

As an example of a method of producing one such dispersion, or defoaming agent, I give the following:40 parts paraiiin wax and 10 parts aluminium stearate are heated until the aluminium stearate is dissolved and 50 parts of sulphonated tallow are added and the mixture is heated to about 75 C. for 15 minutes under constant stirring and allowed to cool.

As an example of the use of the defoaming agent, produced as above, I give the following:- Determine the amount of dry glue in the glue solution to be treated, and add to said glue solution an amount of the defoaming agent equal to two per cent of the amount of dry glue. This mixture should be made at a temperature of 60 C., and when thoroughly mixed, cooled and dried.

My defoaming agent does not separate from the glue as do other suggested defoamers, such as the insoluble greases.

The process of my invention is not limited in its application to glue and similar substances, but can be employed with valuable advantages for the defoaming of other substances, for example paper coating compounds. In employing my defoaming agent to paper making compounds, I allow a small stream of a 5% dispersion of the defoaming agent to run into the heaters connected, with the paper machine. The addition of the defoamer at this point reduces the foaming in the washers at the point where the pulp is run onto the screen. In employing my defoaming agent to paper coating mixtures, I add 1% of the defoaming agent, based on the weight of the paper coating mixture to the latter. I prefer to disperse the defoaming agent in a small quantity of water before adding it to the paper coating mixture.

By dispersed insoluble metallic soaps" I mean the dispersed insoluble metallic soaps of fatty acids, but I prefer to employ the higher melting point fatty acids, as stearic acid and palmitic acid.

Among the water insoluble metallic soaps which I may employ in my process are aluminium stear ate, magnesium stearate, calcium stearate, zinc stearate, manganese stearate and the corresponding palmitates, but I do not limit myself to these particular compounds.

In my specification and claims I do not limit myself to a. single organic solvent, dispersing agent or water insoluble metallic soap, as more than one of the members of these several groups of chemicals can be employed and I refer to them singly only for ease of expression, my invention covering them above and in combination.

I do not limit myself to the particular quantities, times, temperatures, chemicals or steps of procedure particularly mentioned and described, as these are given simply as a means for clearly describing the process of my invention.

What I claim is:-

1. In a process for defoaming foamable products, the step which comprises adding a dispersed water insoluble metallic soap to the product to be defoamed.

2. In a process for defoaming foamable products, the step which comprises adding a dispersed water insoluble metallic soap to the product to be defoamed and heating the mixture.

3. In a process for defoaming foamable products, the step which comprises adding a dispersed aluminium stearate to the product to be defoamed.

4. In a process for defoaming foamable products, the steps which comprise adding a dispersed aluminium stearate to the product to be defoamed and heating the mixture.

5. In a process for defoaming foamable products, the step which comprises adding a dispersed water insoluble metallic soap to glue.

6. In a process for defoaming foamable products, the steps which comprise adding a dispersed water insoluble metallic soap to glue and heating the mixture.

'7. In a process for defoaming foamable products, the step which comprises adding a dispersed aluminium stearate to glue.

8. In a process for defoaming foamable products the steps which comprises adding a dispersed aluminium stearate to glue and heating the mixture.

9. As a new defoaming agent, a mixture oi a water insoluble metallic soap, parafiin wax and a dispersing agent.

10. As a new defoaming agent, a mixture of aluminium steal-ate, paraflin wax and a $111-- pl'lonated organic dispersing agent.

11. As a new defoaming agent, a mixture of aluminium stearate, wax and sulphonateci tallow.

12. As a new defoaming agent, a mixture of a water-insoluble metallic soap, a wax solvent mantis 

